1. Field of the Invention
The present invention relates to a developing apparatus for developing an electrostatic latent image formed on an image bearing member, and a method for assembling such a developing apparatus.
2. Related Background Art
Conventionally, in electrophotographic image forming apparatuses using an electrophotographic process, there has been used a process cartridge which integrally incorporates an electrophotographic photosensitive drum (image bearing member) and process means acting on the electrophotographic photosensitive drum and which is detachably attachable to a main body of an electrophotographic image forming apparatus. By adopting such a process cartridge, since an operator himself can perform maintenance of the apparatus without any expertise, operability can be improved considerably. For this reason, the process cartridge has widely been used in the electrophotographic image forming apparatus.
Regarding a developing apparatus incorporated into such a process cartridge, magnetic seal members such as magnetic seals are provided on both ends of a rotating developer bearing member with a predetermined gap with respect to the image bearing member, thereby preventing leakage of toner (developer).
The magnetic seal members which are not grounded are charged by voltage applied to a developing roller or a developing blade or friction between the developing roller and toner existing between the magnetic seal members, with the result that charges are accumulated in the magnetic seal members. If the magnetic seal members are instantaneously caused approach to the developing blade due to difference in tolerance of parts or any shock, leak will be generated between the developing roller and the magnetic seal members, thereby generating noise. Further, if there is an electrically unstable condition that a developer regulating member is electrically contacted with and separated from the magnetic seals periodically, leakage may be generated between the developer regulating member and the magnetic seals.